Insights into solid acid catalysts for efficient cellulose hydrolysis to glucose: progress, challenges, and future opportunities

Solid acids as heterogeneous catalysts for cellulose hydrolysis have drawn increasing attention; however, current solid acids face challenges such as high catalyst loading (low catalytic activity), poor catalyst-substrate interaction, deficient hydrothermal stability, and unsatisfactory recyclability. This review critically discussed the recent efforts and progress in overcoming the issues of solid acids and developing high-performance solid acids for hydrolyzing cellulose. The key structural features of solid acids and their effects on the interactions with cellulose and cellulose hydrolysis were addressed in detail. Strategies and perspectives to enhance performance, hydrothermal stability and recyclability of solid acids were provided.